: I just installed a new Moen bathroom sink, single handle cartridge style, into our bathroom. I installed a new sink, and I had to install a new P trap and PVC fitting to the wall, since a pedestal sink had been in place before. The new vanity needed a new P trap and fittings to attach to the stub out in the wall. The installation went pretty smoothly. However, during testing for leaks and flushing, I noticed I have one leak.: The Moen faucet came with a grey PVC tailpiece that is 1 1/4" diameter, and is not threaded on the end.: I bought a P trap assembly kit that works with 1 1/2" or 1 1/4" inch fittings. This was the kit recommended to me by the Home Depot guy for installing the new sink. The kit is 1 1/2" white PVC fittings with screw on ends, washers, and reducers. The leak is where the grey PVC tailpiece connects with the 1 1/2" P trap assembly. I put the screw one fitting on the tailpiece, then the plastic reducer it said to use, and then slid the white P trap over the grey tailpiece and tightened it. I did NOT use the washer it came with, as it didn't seem to make sense to stack the plastic reducer and then the washer on next to each other, and it didn't feel like it would allow me to screw the PVC fitting on tight that way. In any event, I screwed on the PVC P trap on the tailpiece and I have the leak. It drips pretty steadily from the top of the screw on fitting when water is running reasonably fast. I've tried loosening it, tightening it and done this over and over to no avail.: Was I supposed to also put the clear plastic washer on, with the reducer, which is basically like the washer except for its reducing action?: How tight should I be going with the screw on fitting?: This may or may not matter but...The tailpiece, as is, is so long that when I slide the P trap onto it and then slide the P trap up until it stops, I bottom it out (that is I hit the bottom of the P trap where it starts its turn). I didn't imagine this was a problem. Although the tail piece sticks really far into the P trap, it doesn't cause any kinks or odd bends, that is I didn't have to force anything, it isn't stressed.: Any ideas?: And I assume no lubes or puttys should be used with the PVC and screw on fittings? I can't seem to get it and I'm at a loss.: Thanks,: Greg

Greg,The 1.5" p-trap will come with slip joint washers for either a 1.5" tailpiece or the 1.25" that you have. The slip joint washer you should be using is the one that reduces in size. You will slip the nut onto the tailpiece and then the reduced size slip joint washer. Everything is a "dry fit" no thread sealant or Teflon tape. These can be hand tightend. Too much tightening and the slip joint washer can split, allowing water to leak out.

If you need to use a new "trap adapter" at the wall, and the pipe coming out is plastic, then you would glue the adapter onto that pipe.

The p-trap itself goes together with the slip fittings.

If the tailpiece is too long, it can be cut. It sounds like that is not a problem with yours. Terry Love